Improvement in furnaces for burning pulverized fuel under steam-boilers



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IIIIHWHI UNITED STATES-#PATENT OFFICE.

l iMPBovEMENT iN FURNAcEs FOR JAMES D. WHELPLEY AND JACOB J. sronnn, or BOSTON, MAssACnUs'urrs.

UNDER sTEAMBo|LER s,

Specification forming part of Letters Patent N0. 111,705, dated February?, 1871;v

To all l'whom 'it may concern.-

Be it known that we, JAMES D. WHELPLEY and JACOB J. STORER, of Boston, Massachusetts, have made a new land useful Improvement in the Constrwctionof I urnaces andCoinbustion-Chambers forBurning Iulverized Fuel under Steam-Boilersfvc., and in setting and arranging the flues and passages of such furnaccs so as to obtain the best results from the use of pulverized fuel kin hea-tin gsteam-boilers, in distillation of liquids, in evaporating salt brines and sacehar'ne liquids, and similar applications of heat; and We hereby declare the following to be a full and exact description of the saine, reference being had tothe accompanyingdrawing, which forms a part of this speciiication.

In our patent of March 1 3, 1866, reissued March 1, 1870, No.7 3,857, we have described a Vgene-ral method of using pulverized fuel which is adapted to all l'the ordinary operations rcqnirin g heat. Y

In our Patent. No. 76,286, dated March 31,

1868, we have described theeonstru'ction of furnaces and boiler-settings so as to secure more perfectly the advantages to `be derived from the use of pulverized fuel.

. Our present'inventionis a stillfurther improveln'ent` upon that covered by the last-mentioned patent..

The first part of'onr improvement consists in4 .adding to the arched combustion-'chamber described in Patent 7 6,2803. series of other narrow arches under the boiler, so arranged as to deflect and break up the current of fuel and flame asit passes under the boiler or through the combustion-lines second, in hanging the, boiler in such a manner asI to; have a clear hearth and flue under it, so thatthe ashes may be more readily removed andthe burning of the supports preyented; third, in the arrange- `lnentot'` an ash-pit so astorcceive the ashes as removed'from the fines fourth, in the combination of combustion flues andchannels hav according to' our invention. Fig. 2 shows a method of supportm g the boiler so as-to. leave 1 the ,uesaud passages unobstructed: Fig. 3` is a cross-section in tlie line z z of Fig. 1. Fi gs. 4 and 5 are'similar cross-sections in the lines y y and w a: of Fig. 1*.

The same letters indicateA likecparts in all the figures.

Our invention may-be applied 'to all kinds come further developed,fwc have found that great advantages are gained by the following improvements inthe setting ot' a boiler. lhe plan is especially applicable to ilue,tubular,

or plain cylinderI boilers set horizontally, to

fwhich it has been applied. Some modifications, involving, however, no departure from` theprinciple, would be'necessary to adapt it to other. boilers. f

We retain, as features in this our new method, the.concave hearth under the boiler,

which radiates the heat toward its longitudinal axis, the small lire-box and grate-surface, and the brick arch (preferably without perforations) thrown over the lire-box, to serve as a radiator of heat upon the column of entering v pulverized fuel and air and upon the fuel on the grate.. l

We prefer now1 to have the arch over the fire-box extend inward from' the boiler-front.

but about eighteen inches to two feet, Aor only so far as to ,offer so much heat-radiating surface that the gases of the fuel may be well distilled and ignited before they come under the influence of the heat-absorbing boilersurface beyond the arch.

In using pulveriaed'fuelf the coal particles,

upon the distillation of the gases from them, v 'become particles ofcoke, which burn with more or less ,readiness While floating along in the projected burning gases. In a heated furnace, from every portion of the interior walls ofwhichheaais radiated-,

vthese ininutc floating particles ol carbon are i'ace that the current of' ga-ses and floating care- .y

bon comin g iii contact with the boiler is quickly cooled below the point of combustion, the result beingfgreater, 4org less loss of fuel by escape by the stack, and deposition in ash-pits,

tubes, and' ilues'fof. ungonsuined earboli.

iVhen a fire burns under a boiler without` blast, withonly a naturaldraft, thefcolunin of.`

ilanie indi siidoiigj iraii almost undisturbed current,m Isenting only its upper surface in contact" shown its heat is so quickly, absorbed 'by this. contact that incandescence'"ceases within ay short distance.

Oneot" the eminent adrantages of a'blast.l under theire-place', ,accord'ii'ig to Professor Rankin 'and-other authorities, is that it breaks up or causes to reverberate thisotherwise` smoothly-flowing currentoi' dame, and makes it presei'it frequently to the-boiler fresh incandescent surfaces. .It is evident, then, that to obtain "u'nderf a boiler the lfullest value from the iaifne'itl should be made to reverberate as much "'-possible,in order that it may present to theboile'r allftheheating-surface it is capableofvdoing. f

Ourn'rethod of obtaining this desirable reebuild a succession of brick arches or their equivalents' as radiators and deectors, as shown 'ndrawirng, at intervals oi' two feet, inoreor less-,l'iindertlie boiler throughout its len llhe'searches or deflectors give excel-- lentjresults;*whether theybe four and a halt inehes or 'iiiii'einelies wide-f-i-., the'l'eiigtlroil a hallf or of a whole brickbut may be made eonti'niioii'sgwith openingsto admit hot air to' thcjbottoinotftlie'boileig'if desired.

Whether the fuel be coiisu'medin the usua wayY on gratos,orpulverized fuel'fbe used ac- 'ing toxcuyinethod, the column of ilaine parts. with much of its heat. by'riiiar'eltfit's forward motion is checked, and its'is iliade' to .reverberatey andv r'ollabout, so tlia'titj presents a fresh heatingsurface to the bo'itoiot the boiler in `the exposed ,space above and between'the first and succeeding'v archd''lhis action is repeated by each succes- -sive'ar'ch for l the length ofthe boiler until, "to the limits of practicability, th'e llanie 'has given up its heat.

After a few hours of work. the arches become sulliciently heated to radiate heat, thus insuring, as an additional `advantage to their disturln'niee ot the flame, a more complete combustion of' whatever unconsnmed gases and particles o, carbon may be passing under ithy the boiler, and observation has,

n lesistible` tendency presents itsupperk surface to VlStlie boiler, and almost instantly If interrupted 'the boiler. By this arrangement the ashes and tloating particles of carbon are detained and precipitated upon the hearth, instead of and tubes.

In the drawing, A. is the first arch, extending entirely or partially over the lire-place. B B B are the narrow arches, set at intervals ot' v the length of the boiler. (l is the last arch, at ,.the rear end ot' boiler.

The space above the arch C, between it and theboiler, is filled up with brick, to atl'ord a check to the easy passage ofthe iloatingxdust and ashes into the tubes orA ilues, and to cause thenirather to deposit on the hearth or in the .rear asin-pit, aiid to create Afull reverberation of the flame. 4

lhe arches l5 l B permit the flame to pass over and lunder them. l) D D are the intervals between the arches, where the llame more readily is presented to boiler-surlace. A

`. Usually, standards ol' cast iron, resting Von boiler. NVe dispense with these, and, instead, use a wrought-iron support or supports, E, as shown in drawing. By the use ot' these the hearth' is leitclear and without obstruction, so that the ashes lodging thereon can easily be removed by a proper tool; besides, the heat soon destroy the usual standard.

The support` E is guarded bythe brick arch (j. As many ci these supports as are required may be. used. i

l-l is the rear ash-pit, for the reception ot' the ashes that maybe precipitated into itl'rom the .moving column of llame, and for what may be pushed or drawn into it in eleaningthe tubes, lines, or hearth.

When using p i'ilverized fuel most ot' y the ashes deposit on the hearth; and when it has accumulated seas to be likely to oller an ob struction to the draft, it mu'st be pushed or drawn into the ash-pit, whence it may be reveilt the rising ofthe4 dust. y or depository should have a removable cover;

the hearth, or at anyplace under the boiler, in whichthe ashes may be collected, land whence it can be conveniently removed. v

i `l'llvie arches A, l D Ill, and (l, or their equiva` lents, are oi" great adyantage, whether liring,

. ratei-s, and therelere the blastheating appa inovingrforward andI depositing in the liliesthe hearth, are employed for sustaining ythe under a boiler set according to ourA plan would moved after beingspi-'inkled u'itlrwatcr to pre This rear ash-pit but a pit or pits may be made at veither end ot'` asis usuahwithluinp or solid i'iielor ith lump.: and pulverized, as by our method. Se', also, .is t-lie concave hearth extending nnde'rthe boiler;

- where fresh fuel is added there should be provided, to insure best results, a supplementary arched combustionchamber, so aslto 'secure perfect burning or gasifyiug of the fuel, as

hereiubefore explai ned.- .Lhese improvements, though especially designed for burning pulverizedv fuel, are also applicable when lump-coal, ,\\}ood, or other solid fuel is used, and also in the use of gaseous fuel.

Though we prefer the'concave hearth under the boiler, in combination with' thc arches, o11

account of its superior ei'ect, to lche -usualat' hearth, or to the common heart-h, broken-or interrupted by pits or chambers, still We might, nndcjsoine circumstances, use or retain either ci' 'these 'in combination Vwith' the arches.

Harin gtlius described our i1-1vcntiou,\vliai3 We claim, andklesirc to secure by Let-ters Patent ofthe United States', s-

l.. The arched coinbustioirchanibcr, in combination with grate-bars, and separate blast: to

the combustioilechamber and under the graebars, substantially as and for the purposes described.

2. The arrangement of a series of arches or deilectors'under a boiler orvv evaporator, so -to break up' and deflect Jche current of lame and gas,- substantially as described.

A v 3. ,The combination ofthe arches B B B and C andthe concave hearth, as shown 'and described. 1-

4. The arrangement of'. the ash or cinder receptacle with the combustion-fines, as described.

5. The conibiuationof the solidly-arched conibnstion-chaniber with the" reverberatiiig-ihres and the supporting;and-deilecting arches, sub stantially as described.

A G. The device shown i'u Fig. 8, for supporb ing the boiler over the concave line, i'or collectn ing the cindcrs, as described.

Witnesses;

' G11-ARLES M. NicKERsoN,

Faun. W.. LoNeLEY. 

